Device for cleaning the walls of boreholes



A. E. ATKINSON DEVICE FOR CLEANING THE WALLS OF BOREHOLES Aug. 24 1954Filed Nov. 27, 1950 InI enfO/j A/be fEdw. Afkinaon, 15 /W Patented Aug.24, 1954 DEVICE FOR CLEANING THE WALLS F BOREHOLES Albert EdwardAtkinson, Hinchley Wood, Esher, England Application November 27, 1950,Serial No. 197,697

Claims priority, application Great Britain November 29, 1949 6 Claims.

This invention relates to devices for cleaning the walls of bore holes,of the kind comprising a plurality of stiff wires or wire bristlescarried by a ring which is adapted to be mounted on the outside ofthebore hole casing, the wires extending outwardly from the ring andarranged so that by reciprocating the casing in the hole the wires exerta scratching action for cleaning the wall by the removal of caked mud orthe like therefrom. Such devices are primarily intended for removingcaked mud from the bore hole immediately before the casing is cementedin the hole. The wires of such devices are liable to be subjected tovery considerable strains during use, as for example due toirregularities or changes in direction of the bore hole, and as a resultthe wires are sometimes torn from the ring to which they are attached.It is. the object of the present invention to provide a stronger andmore effective attachment for the wires whereby the above disadvantageis largely or wholly overcome in a simple and convenient manner.

The invention consists in a device of the kind described comprising amounting ring having a continuous sleeve or sheath to the interiorsurface of which the wires are attached so that the attachment iscompletely shrouded and protected, the attachment being preferablyeffected by the aid of metal cleats or cover elements welded to the saidsleeve or sheath.

The invention further consists in a device according to the precedingparagraph in which the wires are doubled or folded in two and the foldedends are secured said sleeve or sheath which constitutes part of themounting ring. Preferably the folded ends are of narrow U-shape and aresecured by the aid of metal cleats or cover elements having acorrespondingly U-shaped recess.

In a preferred arrangement according to the invention, the ring carryingthe wires is formed or provided with a peripheral portion or portionsadapted to fit and engage the bore hole casing, and with an adjacentperipheral portion of larger diameter to the interior surface of whichthe wires are secured. The portion of larger diameter may convenientlybe connected to a smaller portion by a shoulder in which apertures areprovided through which the wires project. Preferably the ring is formedin a single piece by a swaging, spinning or like operation and comprisesa middle sleeve or sheath of larger diameter integrally joined byshoulders to concentric portions of smaller diameter at each endthereof.

to the inside of the afore- The wires employed may be of any suitablecharacter, but preferably bundled or stranded wire is used. and theprojecting wire portions are provided with one or more small metalsleeves or thimbles secured thereto and suitably angled to impart adesired directional set to the wires. It is to be understood that thewires are uniformly spaced about the axis of the mounting ring andpreferably they are inclined to the said axis, including the end portionof the wire which is secured to the interior of the sleeve or sheathpreviously described. Those portions of the wires which project from theaforesaid apertured shoulder are formed to extend outwardly in agenerally tangential direction and this setting of the wires ismaintained by the small sleeves or thimbles referred to above.

In the accompanying drawing,

Figure l is a sectional elevation of a device constructed in accordancewith the invention for cleaning the walls of bore holes, the sectionbeing taken on the line X-X of Figure 2;

Figure 2 is a plan view of the device;

Figure 3 is a side elevation of one of the metal cleats employed forsecuring the wires;

Figure 4 is an end view of one of the cleats.

In carrying the invention into effect according to one convenient mode,a metal ring is provided in the form of a cylindrical sleeve comprisingend sleeve portions l, l integrally joined to an intermediate sleeveportion 2 of larger diameter by shoulders 3, All three sleeve portionsare concentric. The end sleeve portions 5 are dimensioned to fit overthe bore hole casing, and the diameter of the intermediate sleeve 2 issuch that the ends of the scratching wires can be convenientlyaccommodated within it. The ring or sleeve as described above may beformed by a swaging, spinning or like operation.

The wires 4 which constitute the cratching or wall cleaning elements maybe of any suitable character as previously employed in such devices, butpreferably they are bundled or stranded wires of suitable size andstiffness. Each wire is doubled or folded in two in the form of a narrowU-shape. The sides at the folded end are preferably parallel but theremaining portions may be slightly splayed if desired as shown inFigure 1. The folded ends or bights are secured to the inside surface ofthe intermediate sleeve portion 2 of the ring or sleeve and suitableholes 5 are provided in the adjacent shoulder 3 through which the endsor standing parts of the wires project. The said folded ends areattached so that they lie substantially parallel to the casing wall andextend obliquely with respect to the ring axis, the angle being widelyvariable, but may be in the neighbourhood of 45. The attachment of thefolded ends is efiected by the aid of metal cleats or cover elements 6each of which is formed with a U-shaped recess 1 which encloses the U-shaped wire fold, the edges 8 of the cleat or cover being welded to theinterior surface of the intermediate sleeve 2, preferably by spotwelding. The Wires may be further secured by soldering them inside thecleats before attachment of the latter, or by indenting the cleat afterattachment, or by both means. The cleats abut the shoulders 3 and thisarrangement aids in securing the cleats in position.

The ends of the wire which extend outside the sleeve shoulder are formedto extend outwardly and also in a generally tangential direction withrespect to the ring axis as shown in Figure 2. One or more small sleevesor thimbles 9 are secured over the free portion of the stranded wires toensure the required setting thereof. Thus two sleeves 9 may be providedfor each projecting wire, one near the sleeve shoulder and one neartheir original positions after use so that tangling is obviated.

1. A device for removing caked mud and thesecuring said U-shapedportions to said ring.

2. A device according to claim 1, said securing means comprising coverplate means positioned within the space afforded by said skirt portion,

4 welded thereto, and internally abutting said shoulder portion, saidcover plates having U- shaped grooves therein embracing said U-shapedbight portions.

3. A device according to claim 2, said cover plates having portionsthereof substantially bridging the space between said skirt portion andthe wall of the bore hole casing.

4. A device for removing caked mud and the like from the walls of boreholes, comprising a ring adapted to be mounted on the outside of a borehole casing, said ring comprising a portion having an inside diameterfitting the casing, a. shoulder portion extending outwardly therefrom,and a skirt portion connected to said shoulder portion and of a size forenclosing an annular chamber about the bore hole casing, a plurality ofseparate mud cake scratching wires each having a U-shaped bight in itscentral portion and an upstanding portion at each end of said bight,said bights being disposed in said annular chamber generally parallel tothe bore hole casing wall and said upstanding portions extending throughsaid shoulder portions in spaced relation to each other and being turnedoutwardly therebeyond, and means within said annular chamber forsecuring said bight portions to said ring.

5. A device according to claim 4, said securing means comprising coverplate means positioned Within the space accorded by said skirt portionand weld-ed thereto, said cover plate means having U-shaped groovestherein embracing said U- shaped bight portions, the spacing of saidskirt portion from the bore hole casing being substantially justsufficient to accommodate the bights and cover plate means therebetween.

6. A device for removing caked mud and the like from the walls of boreholes, comprising a ring adapted to be mounted on the outside of a borehole casing, said ring comprising a connecting portion fitting thecasing and a skirt portion References Cited in the file of this patentUNITED STATES PATENTS Number Name Date 1,040,808 Stork Oct. 8, 19121,970,302 Gerhardt Aug. 14, 1934 2,421,434 Reistle et al. June 3, 19472,427,632 Stephens Sept. 16, 1947 2,634,813 Wright Apr. 14, 1953 OTHERREFERENCES World Oil, April 1949, page 256. (Copy in ScientificLibrary.)

